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Oct. 3, W. F. SCHEEL AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet 1 BY /W ATTORNEYS Oct. 3, 1961 w. F. SCHEEL 3,002,762 1 AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet 2 I VENTOR ATTORNEYS W. F. SCHEEL AXLE ASSEMBLIES Oct: 3, 196 1 14 Sheets-Sheet 3 Filed Sept. 6, 1957 LII R M mi x Get. 3, 1961 l w. F. SCHEEL 3,002,762

AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet 4 1N VENTOR #n/ae [55956;

ATTORNEYS W. F. SCHEEL AXLE ASSEMBLIES Oct. 3., 1961 14 Sheets-Sheet 5 Filed Sept. 6, 1957 ATTORNEYS W. F. SCHEEL AXLE ASSEMBLIES Oct. 3, 1961 14 Sheets-Sheet 6 Filed Sept. 6, 1957 ATTORNEYS W. F. SCHEEL AXLE ASSEMBLIES Oct; 3, 1961 14 Sheets-Sheet 7 Filed Sept. 6, 1957 A 5 mm n g m m? 7 w W W A Oct. 3, 1961 w. F. SCHEEL 3,002,762

AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet 8 INVENTOR ATTORNEYS Oct. 3, 1961 w. F. SCHEEL 3,002,762

AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet 9 Oct. 3, 1961 w. F. SCHEEL 3,002,762

AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet l0 ATTORNEYS Oct. 3, 1961 w. F. SCHEEL 3,002,762

AXLE ASSEMBLIES Filed Sept 6, 1957 14 Sheets-Sheet 11 mlllllllfl Illlllll INVENTOR 2km [SQ/e6;

ATTORNEYS (jet. 3, 1961 w. F. SCHEEL/ 14 Sheets-Sheet 12 Filed Sept. 6, 1957 5/6 INVENTOR firs 652 564664.

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ATTORNEYS W. F. SCHEEL AXLE ASSEMBLIES Oct. 3, 1961 14 Sheets-Sheet 13 Filed Sept. 6, 1957 INVENTOR %7A/6/.Z 6C//66L ATTORNEY5 4W muifiumo i lll r Oct. 3, 1961 w. F. SCHEEL 3,002,762

AXLE ASSEMBLIES Filed Sept. 6, 1957 14 Sheets-Sheet 14 ATTORNEYS United States Patent 9 3,002,762 AXLE AESEMBLIES Walther F. Scheel, Detroit, Mich., assignor to Rockwell- Standard Corporation, a corporation of Pennsylvania Filed Sept. 6, 1957, Ser. No. 682,531 11 Claims. (6!. 280-815) This invention relates to improvements in vehicle axles and suspensions and has particular reference to dirigible tandem axle assemblies.

It is the primary object of this invention to provide a dirigible tandem axle assembly embodying the features of stability, over-all ruggedness and a spring suspension which distributes the load equally on both axles that have been heretofore built only into non-dirigible tandem axle assemblies while providing a short turning radius and ease of steering through a steering control linkage in which front wheel steering is proportioned by a pitman arm between axles and by steering cross tube arms and cross tubes on each axle in such a manner that the dirigible wheels turn about a common center located substantially on a lateral extension of the laterally extending center line of the rear tandem drive axle assembly.

A further object of the present invention is'to provide a dirigible tandem axle assembly embodying either driving or non-driving axles and which provides free pivoting and vertical displacement of the axles to conform to ground irregularities while assuring maximum stability of the assembly, ease of steering and a small vehicle turning radius by construction 'and arrangement of the I stabilized whereby the steering linkage and suspension are substantially relieved by the torque rods of vibration and torque induced stresses.

Another object is to provide a low center of gravity in the spring suspension for dirigible tandem axle assemblies.

A further object of this invention is to provide an improved dirigible tandem axle assembly of the type described of such improved construction and arrangement that the axis of the cross tube journallecl on the leaf spring suspension is located in a horizontal plane at least as low as the plane defined by the axle axes or below such plane.

A further object is to provide a dirigible tandem axle assembly embodying completely stabilized axles each positioned by a parallelogram system of torque rods and a sway bar linkage for keeping the tandem axle assembly and chassis centerlines substantially in perpendicular relationship at all times.

Further objects of the present invention will become apparent from the following description, when considered in connection with the accompanying drawings and the appended claims,

In the drawings which illustrate several simple and practical embodiments of the invention:

FIGURE 1 is a side view of an eight wheeled vehicle embodying a rear tandem drive axle assembly and a front dirigible tandem axle assembly in accordance with the present invention;

FIGURE 2 is a fragmentary top plan view of a dirigible tandem axle assembly having non-driving dirigible axles constituting a first embodiment of the present invention;

FIGURE 3 is a fragmentary side view of the assembly of FIGURE 2;

FIGURE 3A is a fragmentary view showing the forward extension of the steering mechanism of the assembly as illustrated in FIGURE 3;

FIGURE 4 is a fragmentary sectional view taken sub: stantially along line 4i4 of FIGURE 2 showing trunnion tube mounting seat spring and pitman arm details;

FIGURE 5 is a fragmentary rear end View partially in section showing the rear axle of the tandem axle assembly shown in FIGURES 2 and 3 and taken sub! stantially on line 5-5 of FIGURE 2;

FIGURE 5A is a fragmentary sectional view taken substantially along the line 5A-5A of FIGURE 5;

FIGURE 6 is a fragmentary top plan view, similar to FIGURE 2, of a dirigible tandem axle assembly having live steering axles and constituting a second embodiment of the present invention;

FIGURE 7 is a fragmentary side elevational view, partially in section, of the assembly of FIGURE 6;

FIGURE 8 is a fragmentary rear end view, partially in section, showing the rear live steering axle of the assembly shown in FIGURES 6 and 7;

FIGURE 9 is a fragmentary side elevational view, similar to FIGURES 3 and 7, of a further dirigible tandem drive axle assembly constituting a third embodiment of the present invention;

FIGURE 9A is a fragmentary view of forward extension of the steering linkage of the assembly of FIG- URE 9;

FIGURE 9B is a fragmentary rear end view of the assembly of FIGURE 9;

FIGURE 10 is a top plan view of a dirigible tandem axle assembly having live steering axles and equipped with lateral axle stabilizing means constituting a fourth embodiment of the present invention;

FIGURE 11 is a fragmentary transverse sectional view of FIGURE 10 taken substantially along the line l111 of FIGURE 10 and showing the lateral axle stabilizing means;

FIGURE 12 is a fragmentary plan view of a tandem axle assembly embodying another axle lateral stabilizing means and constituting a fifth embodiment of the present invention;

FIGURE 13 is a fragmentary transverse sectional view of the axle and lateral stabilizing means of FIGURE 12, taken substantially along the line 13-13 of FIGURE 12; and

FIGURE 14 is a fragmentary rear end view of th assembly of FIGURE 12. 1

With reference to the drawings, FIGURE 1 illustrates an automotive vehicle It embodying a rigid frame 12 having rigidly interconnected longitudinally extending parallel side frame members 14- supported at the rear by a non-dirigible tandem drive axle assembly 16 and at the front by dirigible tandem axle assembly 18 which may embody either driving or dead (non-driving) axles as will become apparent presently. Vehicle 16 is equipped with engine 29, a cab 22 located over the engine 20, and a drive train (partially described in the following) from engine 20 to tandem drive axle assembly 16 and, if assembly 18 is also equipped with drive axles, to assembly 18 through a transfer case in accordance with conventional practice. Both tandem axle assemblies 16 and 18 have floating spring suspensions 24 and leaf springs of which are centrally pivoted on a transversely extending trunnion 26 which is mounted by bracket assemblies 28 beneath the frame 12. Wheels 3% and 32 are mounted on dirigible axles 38 and 40 respectively of dirigible tandem axle assembly 18 and wheels 34 and 36 are mounted on drive axles 42 and 44 respectively of rear tandem drive axle assembly 16. Use of floating type spring suspension 24 at both rear and front tandem axle assemblies '16 and 18 maintains framelift at the tandem axle assembly at one-half obstruction height as one wheel (steering wheels 30 or 32 at the front tandem axle a-sseniblylfi and drive wheels 34 or '36 at the rear tandem axle assembly 1-6) of the tandem axle assemblies passes over an obstruction. 'Frame twist at the front of vehicle 11) 'is half or less than'half the frame twist which is encountered at the front of single front axle vehicles for an obstruction of any given height.

Referring to FIGURES 2 through '5, a preferred embodiment of the invention is therein disclosed embodied in a dirigible tandem .axle assembly .18 having closely spaced dead (non-driving) axles 3t; and ill the axle beam of each having 1 section center portions 46 extending between axle mounted spring end brackets The 'I section of the axle beams continues from .center portions 46 through enlarged 1 sections as (see FIGURE 2), at which spring endbrackets 48 are fixed to the axle by bolts 52, and then gradually changes to an oval section 54 (see FIGURE 5) adjacent the .axle :king pin boss 56. Referring again .to -FIGURE 2, spaced parallel longitudinally extending leaf springs 53, only tone of which is shown, extend between .and rest at their op ,gposite ends onthe axles 38 and -40, their ends as each resting on the convex surface dz-of a pillowlblock .64 disposed :within a through opening 6:: in lbracket iti. .The fstirrup like openings .66 in'brackets 43 restrict rebound of the ends of springs 58 and .assistin maintaining axles "3 8 and 40 'in lateral alignment withrespect ,to theirarne 12, leaf springs 58 acting as alignment members. A clearance is providedin brackets 43 between side abutting surfaces as and the side edges of the springends an :toallowlimited axletracking self-alignment and free articulation of the axles, within limits, toaccommodate iground surface irregularities.

As.is most clearly illustrated inFlGURES 2,3, and 4,ithe front end of vehicle frame .12 is pivotally suspended between axles 38 .and 4.0 at the center .of leaf Springs .58, springseats 7t} whichvare clamped to the centter of springs 58 being mounted for oscillating rocking .movement .ontheeends of the transversely extending .trun- Iiion tube 72 which is fixed between upwardly extending lframe-support assemblies 28 thatv are fixed to vframe 12. A machined channel 174 (FIGURE 4') in rfidCll spring 'seat 70 snugly holds at least the lowest main .leaf .76 of the leaf spring 58. Leaf springs 58 are clamped to spring seats 70 by U bolt assemblies 78. With this construction any axle aligning function of :each spring '58 .is e'fiectedsolely through the main .leaf'or leaves 7.6 which 'areheld'by seat '70. Leaf springs 58, due to theircentral ,lpivotal .connectionto frame. 12, divide the front axle i load 6f the vehicle equally between axles 'dhzand dii and provide resiliency which adds to the shock-reducingaction in the above described balanced spring arrangement to give a cradle sup-port for the front endofframe 12.

Referring to FIGURES 2 and 3, axles 3d and dilate each connected to frame bracket assembliesls by upper and lower parallel longitudinally extending-torque rods "80 provided at each side of the longitudinal centerline of ftandem axle assembly 18. Upper torque .rods tiil' are universally equipped at each end with rubber hushed ball end stud assemblies .82 of the type disclosed in detailrin copending application Serial No. 623,858 filed December 6, 1956 .by James .M. Prange for Universal Joint, and havinga common assignee with the instant tcase,rthe studs of assemblies .82 atone end o-ftorquerods 80 being received in ,openings d (FIGURE 4) of frame bracket assemblies Ztiandthestuds of assemblies 82st the other ends of torquerrods 86) .being received through an upwardly extended boss 36 (FIGURE 5,) of axle brackets 48. Lower torque rods 8d are universally mounted at one end in openings 88 (FIGURE .4) of vframe bracket assemblies 28 and at the other ends on the downwardly extended .arms9ll i (F IGU RES 4 and :5

of axle brackets 48 by rubber bushed ball pin assemblies '32. This arrangement provides dirg'ible tandem axle assembly 18 with a parallelogram system of torque rods connecting each of the axles 38 and 40 to the frame 12 through brackets "23. Torque rods 80, which act like a pantograph, transmit all braking and any other 'torsional'forces that may be imparted to the axles 38 and 4'0 to vehicle frame and restrain axles 38 and as from rotation about their axes while permitting vertical displacement and tipping of each axle to accommodate ground surface irregularities.

Referring to FIGURE 5 in which the axle outer end construction is shown in detail, at each end of axles 38 and 40 a king pin 92 having a-centrally tapered shank '94 is tightly seated at its tapered central region in tapered opening 96 of the steering knuckle boss 56 and pivotally mounts a steering knuckle 98. Steering knuckle 98 is formed with an upper boss 1% .apertured at .102 and journalledby bushings 104 on upper cylindrical end portion 196 of the king pin shank 94 and with a lower boss 19.8 apertured at 113 and journal-led by bushing 112 on the lower cylindrical end portion 114 of .king pin shank .94. Each king pin d2 is tightly seated .in the steering knuckle boss opening 96 by a nut .116 abutting the inner .one of the two concentric bushings 1'04 and threaded on the threaded end portion 118 at the top of and integral with the king pin 92. The center section 1123 of steering knuckle 93 between .bosses .100 and .108 is formed with a cylindrical shoulder 11-22; from the outer face .of which an integral wheel spindle projects. In this embodiment king. pins 32 are so inclined, as 'for ..example at an angle of 18 from the vertical toward the center of the vehicle frame, as to reduce tire overhang without encountering an undesirable amountof axle center lift when steering knuckles 8 are turned about the axis of kingpin 92. Wheel spindle 124 is formed :with threads 1216 at its outer .end to .receive a wheel adjusting nut 12d. Spaced opposed tapered .roller thrust bearings 13.? and 132 are providedouspindle .124 to journal wheel hub 134. and brakedrum .136 which is coaxially fixed to hub 13 by bolts 13.7. (The wheels .30 and '32 'are mounted on lhubs .1314 of axles .38 and as respectively by bolts i37a .in the conventional manner. A brake backing plate 133, which supports a cam actuated internally expansib le brake mechanism assembly 14ft concentrically within the drum 136, .is fixed to steering knuckle shoulder 122 by rivets 142 circumferentially spaced about the axis of spindle .124.

A set screw and lock nut assembly 144 is mounted in threaded opening .146 .ofeachsteering knuckle center section '120 for adjustment to .limit wheel turning angle 'by abutment withboss 148 on the axle boss 56.

As is most clearly shown in FIGURES 2 and 5 and 5A, upper steering arms 15% and 152 of axles 38 anddi) respectively, which .are connected to the steering linkage .as will be explained presently, are received and fixed in tapered apertures .153 formed in the end region of upper bosses 190 of the steering knuckles 98 associated with the wheels .of assembly 1 8 at-the left side of the vehicle 10. Lower steering arms 154 and 155, whichform part of the interconnections between the wheels of the opposite ends of axles '38 and 40respectively, are fastened to the lower bosses 1.08 of .each ofthesteering knuckles 98 of the assembly 118. Steering arms 150, .152, 1-54 and 155 are .rigidly attached .to the respective bosses and 108 by atconnecti'on-formed .by the coaction of their tapered end :regionswith .the similarly tapered. open- .ings through bosses liltland 108, keys 158 preventing vrelative rotation 'therehetween, and nuts 166 received and tightened on the threaded end region .162 of .each .arm tohold the-parts in rigid-assembly "Upper steering "arm extends axially inwardly from the upper steering knuckle boss 109 of the left wheel 30 of axle 38 as is shown in FIGURES 2 and S -and has a ball stud assembly 168 fixed thereto at its inner end. Stud assembly 168 projects upward from arm 150 and forms part of a universal joint connection 169 with the forward end 170 of adjustable length front drag link rod 172. End @170 is threaded at 173 into the internally threaded hollow end of rod 172, and fixed relative thereto by a lock nut 174. Upper steering arm 152 on rear wheel 32 extends axially inwardly and upwardly from the upper steering knuckle boss 100 of the left wheel 32 of axle 40 and has a ball stud assembly 168 fixed to the end thereof which projects downwardly to form part of a universal joint connection 175 with the rear end of a similarly adjustable length rear drag link rod 176. A downwardly depending pitman arm 178 (FIGURES 2, 3, 4, and is axially fixed on and pivotally mounted on a stub shaft 180 carried by a bracket 182 which is bolted at v184- to the left side of member 14 of frame 12. The rear end of front drag link 172 is universally connected at 186 by a ball stud assembly 168 with the lower end of the inside of pitman arm 178. The forward adjustable length end of rear drag link rod 176 is connected by a universal joint 188 cmbodying a ball stud assembly 168 to pitman arm 178 at a position higher and closer to the pivot axis of pitman arm 178 than the universal joint connection 186 of front drag link v172 and is located on the outside of pitman arm 178 as is most clearly shown in FIGURE 4.

Referring to FIGURE 2., drag link 172 is bent so that it extends forwardly above spring 58 from universal joint connection :186 from the inside of pitman arm 178 and then angularly outwardly to universal joint connection 169 at a position in which it cannot interfere with the turning of the left front wheel. Greater drag link clearance for left front wheel 30 is provided than for left rear wheel 32 with drag link 176, which extends substantially straight back from universal joint connection 188 from the outside pitman arm 178 to universal joint connection :175, because for a given turning radius of the vehicle, the front wheels 30 must turn in greater amount than the rear wheels 32 of assembly 18. This arrangement assures a minimum turning radius while maintaining the simplicity of the steering linkage and permitting use of a linkage which will assure tracking of all four wheels of assembly '18 substantially about a common center during turning.

In the preferred embodiment of FIGURES 2-5 there is a difference in the distance between the pivotal center of steering knuckle 98 of the front axle 3d at the left front wheel 39 and the universal joint connection 169 and the corresponding distance between the pivotal center of knuckle 98 of rear axle 40 and the universal joint connection 175. This difference in distance and the relative angular dispositions of universal connections 169 and 175 as related to the respective pivotal centers of steering knuckles 98 helps to insure that wheels 30 and 32 on the left side of front tandem axle assembly 18 track substantially about the same center at any particular adjusted position through the entire steering range. Another factor which helps insure the proper tracking and correct wheel turning angles for left wheels 30 and 32 is the different spacings of the universal joint connections 136 and 188 from the pivot axis of pitman arm 178. Because of these linkage factors, any given movement of pitman arm 17% has a greater turning efiect upon front left wheel 36 than upon left wheel 32.

A main steering drag link rod 2% is connected to pitman arm 17%; by a universal joint connection 202 embodying a ball stud assembly 168 fixed to pitman arm 178 at the inside of the arm 1755. Rod 260 is of adjustable length and its forward end is unversally connected by a universal joint connection 263 (FIGURE 3A) embodying a ball stud assembly 168 to a forward steering mechanism pitman arm 2&4. Pitman arm 204 is pivotally mounted at 206 upon a bracket 208 which is fastened to the forward left side member 14 of frame 12. .A drag link rod 210, which is connected by a universal joint connection 211, embodying aball stud assembly 168, to pitman arm 204, extends forwardly and is connected either directly to the ouput pitman arm of a conventional steering wheel controlled worm gear mechanism (not shown) or to the output of power steering means (not shown).

Referring to FIGURES 2, 5 and 5A, lower steering arms 154 and 155 extend toward the vehicle rear and to a lesser extent axially inward from the respective lower steering knuckle boss 14. 8 to a ball stud end assembly 212. Ball stud end assemblies 212, which may be shown in application Serial No. 343,163, filed March 18, 1953, by Leo A. Bixby for Joint, matured into United States Letters Patent No. 2,807,486 issued September 24, 1957, depend from arms 154 and 155 and provide a universal joint connection between lower steering arms 154 and 155 and an adjustable length steering cross tubes 214 and 216. Cross tubes 214 and 216 are similarly connected at their opposite ends to the steering knuckles of the wheels at the opposite ends of axles 3'8 and 40 respectively. The relative angular dispositions of ball stud end assemblies 212 at the ends of lower steering arms 154 and 155 are related in the same manner to the pivotal centers of the steering knuckles 98 to provide properly related wheel turning with a steering axle. This insures that wheels 30 at opposite ends of axle 38 and that Wheels 32 at opposite ends of axle 40, as tied together by cross tubes 214 and 216, turn to track circles at any particular instance about substantially the same center point.

FIGURES 6 through 8 disclose a dirigible tandem drive axle assembly 218 constituting a second embodiment of the present invention. Assembly 218 comprises a pair of closely spaced dirigible drive axles 220 and 222. Axles 220 and 222 are each provided with top mounted carriers 240 with through drive bevel gear input assemblies 24-2. The axle housing 244 of both axle 22b and 222 has a short axle shaft housing extension 246 to the left side of the differential receiving section 247 and a long axle shaft housing extension 248 to the right side of section 247.

Leaf spring assemblies 249 of tandem axle assembly 218 are pivot lly mounted on a trunnion tube 259 by spring seats 251 in the same manner as in the embodiment of FIGURES 2 to 5. Leaf spring assemblies 249 are however, as is most clearly shown in FIGURE 7, elliptical inverted leaf springs the ends of which rest on the upwardly facing convex surface 252 of respective pillow blocks 253 (FIGURES 7 and 8) which are suspended beneath the axles 220 and 222 by spring hanger brackets 254 and 255. Brackets 254 and 255, although similar in most respects, differ in that the torque rod mounting arms 256 which extend down from the inner side of each bracket 254 and 255, are located to the rear at the rear axle 22., and forwardly at the front axle 220 (FIGURE 7). The brackets 254- and 255' supporting the right leaf spring on the opposite ends of axles 220 and 222 are identical to brackets 255 and 254 respectively, being reversed in the mounted positions so that bosses 255 of all of the brackets 254 and 255 are adjacent the longitudinal centerline of assembly 218. Stirrup like openings 257 (FIGURE 8) in brackets 254 and 255 restrict rebound of the ends of springs 249 and help maintain axle alignment of assembly 218 with respect to frame 12 by side contact of stirrup plates 258 with the inner end edges of springs 249.

Brackets 254, 254', 255, and 255' are fixed to the axle housings by bolt assemblies 259 and brackets 26%, 261, 262 and 263 respectively on the top of the axle housings 244, one above each bracket. Brackets 269 and 262, which are mounted on housing extensions 246 at the left side of both axles 220 and 222 have upper torque rod mounting arms 264 which extend upwardly from the inner side of brackets 260 and 262. Torque rod mounting arms 264 are longer-in this-enibodimentthan in the preferredqembodiment of"FIGURES 25 to give a longer torque radius arm since only two upper torque rods one are used instead of fouras in the embodiment o'f FlG- URES 2-5. The bracket 7263 (FIGURE-6) on housing sixtension 1248ofaXle 222 over bracket 2% is merely 'a bolt clamp plate over the top of the axle for mounting thebracket 255 under the axle.

Bracket '261 :on housing extension 2% of axle 226, in addition to being a bolt clamp plate over-the top of the axle for mounting the bracket 254 under the axle, has a boss 272 for :rigidly mounting a bail pin assembly 274. Ball pin assembly 274 forms part of a universal joint connection 27S toone end of sway bar 234} Whichextends \diagonally across the assembly 218. The other end-of -'-sway bar 2% is provided with a universal joint connection 282 to the trunnion bracket assembly 284 fixed to frame 12 at theleft'side of the tandem axle assembly 218. Universal joint connection 2&2 is provided by a lball'pin assembly 'fixedjin an opening in boss 28% on the front oflleft trunnion bracket assembly .Sway bar 280 provides lateral stabilization for .front axle 229 and locates 'axle'220 in transverse relation to framelZ "regardless :of unit articulation. Rear axle 222 is held in lateral alignment by leaf spring assemblies 249.

Upper torque rods "256 are provided at the'left side and lower torque rods 2 66a are provided at both sides of assembly 218. Upper torque rods 265 are universally "connected to frame bracket 234 at their ends adjacent the center of assembly 218 by rubber'bushed ball pin assemblies 289 structurally identical with those used in the first embodiment and at their other ends are similarly universally connected to axle mounted upper torque rod mounting arms 264. 'Lower torque rods 256a are "similarly universally connected at their adjacent ends to the lower portions of trunnion bracket assemblies 284 "and at the other ends to torque rodmounting arms 256 of brackets 254 and 255 and 254 and 255 at'the left and right sides respectively of assembly 218 by rubber bushed ball'pin assemblies 289.

AxlesZ-Ztl and 222 each -contain a conventional gear differential 290 (FIGURE 8), which is journalled on 'carriers 24th, driven by spur gear reduction from the 'bevel gear inputs and are drive connected to oppositely extending -axle shafts 292 extending through housings 246 and 248. At'their'outerends shafts 292 are coaxially "fixed to the input of torque transmitting uniform velocity universal joints 2%. The output of each universal joint 2% is integral with alive spindle 2% which is connected "for unitary rotation with the associated wheel as Will'be explained presently.

The shank'lillll of'a housing and steering knuckle mount element 392 is butt welded at 39 to each end of the 'housings o'f axles 220 and 222. Bowl 3th: of each element 302 partially encloses the associated universal joint 296. An upwardly projecting member 3&3 which is fixed'to the top of bowl 3% provides a king pin like shank 310wl'1ich pivotally supports upper steering knuckle boss 31 2. A downwardly projecting member 314 which is fixed to the bottom of bowl 3% provides a king pin like shank 316 which is coaxial with shank "310 and pivotally supports lower steering knuckle boss 31%. Upper'boss 312 and lower boss 313 are rigidly fixed to cuplike steering knuckle 329. Steering knuckle 320, flange 322 of hollow fixed spindle 32d and brake backing plate 326 for internally expansible brake asse1nbly 327 are rigidly connected together by stud and nut assemblies 328 and pivot as a unit about the common axis ofshanks 310 and'3l6. Wheel hub 33 which is I rotatably mounted on spindle 324 by opposed tapered roller thrust bearings 332 and 334, is connected for unitary rotation with live'spinclle 29?, through hub member 336 -which is'bolted to the outer end of spindle298.

of wheel -hub 330 by stud and nut assemblies 346, :tlrum 342 being disposed in coaxial surrounding operative 1:61ation' to the brake mechanism "327.

Bearing bushings 348,:having radial flanges 350, are hired in =opposed relation in aligned apertures through steering knuckle bosses 312 and 313 for a journal fit'awith shanks Elli and 316. On the left ends of axles 220 and 222, upper bus'hings 348 are attached to knuckles 526 with upper steering arms 352 and S'S' iiby bolts 355. Upper-bushings 348011 the right handside of axles 220 and 222 and all four lower bushings are attached with clamp plates 355 to knuckles 32d bybolts 357. Lower steering'arms 358 (FIGURE 6) at-the opposite endsp'f front axle 220 are integral with front axle steering knuckles 320, project forwardly and are universally connected at 360 to the opposite ends 0f front cross tube 362 disposed in front of axle 22%. Lower steering arms 364 of rear axle 222 are integral with rear-axle steering knuckles 320, project backwardly and are universally connected at 365 to the opposite-ends of rear cross tube 366. Rear cross tube 366k located behind-rear axle 2222 and front cross tube362 is'located in-front of axle 220m) prevent cross tube interference with leaf-spring assemblies 249and with swayb'ar 234).

Upper 'steering'arms 352 and 354 at the left side of tandem axle assembly Z EE-are connectedto a drag liuk rod and steering pitman arm construction substantially identical with that illustrated and described in the einbodiment of'FIGURES 2-5. Referring to FIGURES '6 and '7, this steering linkage comprises a :pitman arm 370 pivoted at 372 upon a bracket 374 fixed to a left side-:o'f

"frame 12 -forpivotal 4 movement about an axis extending transversely of "vehicle frame 12, a straight adjustable ength draglink37-6 universally connected at itsoppos'ite ends to upper steering arm 354 andto theexterior side o'fpitman arm 370, about drag link 37-8 universallyconnected at jits opposite ends to upper steeringarm 352 and the interior side ofpitman arm 37% and having aportion extending forwardly longitudinally of the framefromdts connection with pitman arm 37%) to provide clearance for the left front wheel to assure a small vehicle turning radius as in the first embodiment and a main dink 3 84) universally connected topitman arm 370 at its rear end and extending "forwardly of the-vehicle and connected to the steering mechanism in'the same manner as shown and described in'connection with the first embodiment.

FIGURES 9 through 913 disclose a dirigibletandem drive axle assembly 494 constituting a further embodiment of the invention'comprising closely spaced from andrear dirigible drive axles 482 and 4M adaptedto be supported at their outer endsby ground engagingwheels, a pair-of spaced parallel longitudinally extending leaf Springs 406 extending'between and-resting at their opposite ends upon pillowblocks 468 and 410 on the top-of the housings of axles 402 and tildedjacent their outer'ends, a-transversely extending trunnion-tube 412 extending between springs 406 and pivotally suspended from the center thereof in brackets 414 secured to springs 4% by Ui-bolts 416, and frame support brackets 418.1'ixed to tube 412 adjacent the inner face of 'brackets'4l4-to which the frame m ls fixed. V

Turning of axles 4% and 40d about their own axes'in response-to the application. of'driving and braking torques "thereto is prevented by parallelogram systems of torque rods extending between frame support brackets 4418 and therespective axles 4% and 49d. Axle 4% is stabilized at each end by a longitudinally extending upper torque rod iltluniversally connected at its opposite ends-:tozthe top of the housing of axle dtl'dandsto bracket dl8. :and .at

each endby a longitudinally extending lower torquerrod 422 universally connected at its opposite .ends to the bottom of the housing of axle see and to bracket-.418-beneath the axis of trunnion tube 412 as is most clearly shownin FIGURE -9B. .Theuniversal connectionsat the opposite ends :of the torque ."rods ,are preferably of the nected to the outer ends of the axle shafts and the steer- 7' ing knuckles 432 and 434 are pivotally mounted upon the outer ends of the axle housings in substantially the same manner as in the embodiment of FIGURES 6 to 8.

The steering knuckles 432 at the opposite ends of axle 402 are interconnected by a cross tube 436 extending rearwardly of axle 402 between and universally connected at its opposite ends to lower steering arms 438 fixed to the lower bosses of the knuckles 432. Steeringknuckles 434 at the opposite ends of axle 404 are interconnected by a cross tube assembly 440 extending rearwardly of axle 404 between and universally connected at its opposite ends to lower steering arms 442 fixed to the lower bosses of the knuckles 434.

Steering motion is imparted to steering knuckles 432 and 434 by a linkage comprising a first adjustable length drag link 442 (FIGURE 9A) universally connected at its forward end to a steering wheel controlled pitman arm (not shown) pivoted at 444 relative to frame 12 and universally connected at its rearward end to a lever 446 pivoted on bracket 447 fixed on frame 12 at 448, a second adjustable length drag link 450 (FIGURES 9A and 9) universally connected at its opposite ends to lever 446 and to a depending pitman arm 452 pivotlymounted at 454 upon a bracket 456 fixed to frame 12. The pivot axis of pitman arm 452 is substantially midway between axles 402 and 404 longitudinally of thevehicle frame 12. Pitman arm 452 is connected to an upper steering arm 458 fixed to the upper boss of the left steering knuckle 434 of rear axle 404 by a straight adjustable length drag link 460 having universal connections at its opposite ends to arms 452 and 458 as in the previous embodiments. The brake actuating fluid motor 462 for the left end of axle 404 is mounted upon steering arm 458 as shown. Pitman arm 452 is operatively connected to steering arm 464 fixed to the upper boss of steering knuckle 432 associated with the left end of front axle 402 by a bent drag link 466 having substantially the same configuration as the corresponding drag links in the previous embodiments, universal connections to arms 452 and 464 being provided at its opposite ends of the type disclosed in the previous embodiments. Lateral stabilization of axle 402 relative to frame 12 is effected by a sway bar universally connected to the frame 12 through bracket 447 at 468 (FIGURE 9A) and to a bracket (not shown) fixed to front axle 402. Rear axle 404 is laterally stabilized through the action of springs 406 as in the previous embodiment.

FIGURES l and 11 disclose a dirigible tandem drive afle assembly 500 constituting a fourth embodiment of the present invention and embodying closely spaced dirigible drive axles 502 and 504. The suspension comprising leaf springs 506, trunnion tube 508, spring. attachment bracket 510 pivoted to tube 508 and fixed by U-bolts 511to the center of springs 506, and frame support brackets 512, and the parallelogram system of torque rods comprising upper torque rods 514 and lower torque rods 516 are substantially identical with the structure of the embodiment of FIGURES 9 to 93. Likewise, the steering linkage comprising main drag link 518, pitman arm 520 pivoted on bracket 522 fixed to frame 12, rearwardly extending straight drag link 524 and forwardly extending bent drag link 526 is substantially identical with the steering linkage of the embodiment of FIGURES '9 to 9B. The arrangement of steering knuckles 528 and 530, the upper steering arms 532 and 534, the lower 10 steering arms 536 and 538 and of cross tubes 540 and 542 is substantially identical with the correspondingcozp. ponents of the embodiment of FIGURES 6 to 8.

The embodiment of FIGURES l0 and 11 differs primarily from the previous embodiments in that it embodies a transverse axle stabilizing mechanism 544 associated with each axle 502 and 504 of the general form disclosed in association with a non-dirigible tandem drive axle, assembly in United States Patent. No. 2,750,200 issued June 12, 1956 to W. F. Scheel for Tandem Axle Suspension. The transverse axle stabilizing mechanisms 544 are located intermediate axles 502 and 504 and each comprise an equalizer arm 546 pivotally mounted at its center about an axis normal to the axle axis upon a yokelike bracket 548 fixed to the housing of the associated axle, and a pair of oppositely extending guide rods 550 and 552 each extending transversely of the vehicle frame 12 and universally connected at its opposite ends to equalizer arm 546 and one of the frame support brackets 512 as shown.

Mechanisms 544 prevent movement of axles 502 and 504 laterally of frame 12 without inhibiting tipping of the axles or displacement of the axles toward or from frame 12 to conform to ground irregularities.

The dirigible tandem drive axle assembly 600 shown in FIGURES l2, l3 and 14, constitutes a fifth embodiment of the present invention. Tandem axle assembly 600 comprises a pair of closely spaced parallel front and rear dirigible drive axles 602 and 604, adapted to be disposed beneath the front end of the frame 12 of the vehicle 10 and suspend frame 12 thereon through a suspension comprising spaced parallel longitudinally extending leaf springs 606 and 603 extending between axles 602 and 604 adjacent their outer end, a spring attachment bracket 610 fixed to the center of each of the leaf springs 606 and 608 by U-bolts 612, a trunnion tube 614 extending between and journalled at its opposite ends in spring attachment brackets 610, and frame support brackets 616 and 618 fixed to trunnion tube 614 adjacent the spring attachment brackets at the opposite ends of trunnion 614 and fixed to the frame 12 as is most clearly shown in FIG- URE 13.

Turning of the axles 602 and 604 about their axes in response to braking and drivin torques applied thereto is prevented by a parallelogram system of torque rods consisting of upper torque rods 620 and 622 extending respectively from the top of the housing of axle 602 to the frame support bracket 616 and from the top of the housing of axle 604 and the frame support bracket 618, universal joint connections of the rubber hushed ball type being provided at the opposite ends of torque 620 and 622 as in the previous embodiments. Beneath the plane defined by the center lines of axles 602 and 604 are longitudinally extending torque rods 624, 626, 628 and 630, torque rods 624 and 626 being similarly universally connected at their opposite ends to axle 602 and to brackets 616 and 613 respectively. Torque rods 628 and 630 are similarly universally connected at their rear end to the underside of the housing of axle 604 and at their forward ends to brackets 616 and 618. The manner of mounting of the torque rods to the frame mounting brackets is illustrated in FIGURE 13.

The outer end construction of axles 602 and 604 is of the general form disclosed in the previous embodiment consisting of a steering knuckle 632 pivoted on the housing of axle 602 and providing a hollow spindle support for the wheel hub, an upper steering arm 634 fixed t0 steering knuckle 632 and extending inwardly as shown, and a lower steering arm 636 fixed to the underside of steering knuckle 632. The wheels at the opposite ends of axle 602 are interconnected by a cross tube 638 extending in front of axle 602 and universally connected at its opposite ends to the forwardly extending lower steering arms 636. The wheels at the opposite ends of rear axle .604 are similarly interconnected. by a cross tube 640 extending rearwardly of axle 604 and universally connected at its opposite ends to the lower steering arms 636.

' The steering mechanism connected to upper steering arms 634 of axles 692. and 604 at the left side of the vehicle comprises a main forwardly extending drag link 642 which is operatively connected to the vehicle steering wheel in the manner disclosed and described in connection with the previous embodiments and universally connected to a depending pitman arm 644 pivotally mounted about a transversely extending axis upon a bracket 646 fixed to the exterior of the left side of frame 12 as shown in FIGURE 12. Upper steering arm. 634 of axle 604 is operatively'connected to pitman arm 644 'byia rearwarclly extending straight drag link 6425 which is universally connected at its opposite ends to pitman arm 644 and to upper steering arm 634 of axle 61%. The upper steering arm 634 of axle 6% is operatively connected to pitman arm 644 by a drag link 65%; which is universally connected at its rear end to the innerside of pitman arms 644, extends forwardly from that connection {beneath spring 604 and is bent outwardly substantially mid-way of its length and extents forwardly to its universal connection with upper steering arm 63% of axle .692. As in the previous embodiments this bent construction of the forwardly extending drag link permits turning of the front left wheel to the maximum extent possible with the suspension provided without interference from the steering mechanism.

The embodiment of the invention shown in FIGURES 12 through 14 differs primarily from the previous em- ,bofiirnents in that each of the axles 662 and see is equipped with a lateral stabilizing mechanism disposed above the axle and comprising an equalizer arm 652-pivofv ally mounted about a vertical upon a stud 6545, a pair of guide rods 656 and 651i extending oppositely toward the right and left side of the frames respectively and universally connected at their opposite ends by rubber .bushcdbali joints to equalizer arm 652 and brackets 661i and 662 respectively, which are fixed to the upstanding end wall of the channels of frame 12 as shown in FIG- DRE 12. This lateral stabilizing mechanism permits free axial displacement of ti e axles 6&2 and 653% relative to the frame 12 and free-ti iping movement of axles 6G2 and-604 relative thereto while preventing any relative lateral movepitman arm and/ or ditierent steering arm lengths in s ch a manner that the tandem wheels turn about a common center. It provides cross tube linkage for each steering axle which insures that, for any particular instant during a turn, wheeis at opposite axle ends turn about substantially the same center. it provides front tandem axle assemblies which have parallelogram systems of torque rods. lt provides front tandem axle vassembly spring end axle hangers which suspend spring end pillow blocks be- .neath the axles. It. also provides an elliptical inverted leaf spring with spring ends slidabiy resting on pillow blocks suspended beneath fronttandern axles.

Ihe invention may ,be embodied in other specificjforms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, changes which :comesvithin themeaning and range 12 of equivalency of the claims are therefore intended to be embraced therein.

What is to be claimed and desired to be secured by United :States Letters Patent is:

1. In a vehicle, a tandem axle assembly adapted to be disposed beneath the forward end of a vehicle frame, closely spaced parallel front and rear axles, Wheel mounting assemblies pivotally mounted for steering movement at each end of said front and rear axles, a trunnion tube, a pair "of frame support brackets adapted to be fixed to the vehicle frame at its opposite sides and fixed to said trunnion tube to fix said trunnion tube in transverse rela tion to said vehicle frame, a spring seat mounted on each end of said tube for pivotal motion about the axis of said trunnion tube, leaf spring assemblies, one of said leaf spring assemblies being centrally mounted in each said spring seat outwardly from the vehicle frame and parallel to the longitudinal axis of said tandem axle assembly, one end of each said leaf spring assembly resting .on each of said front and rear axles, oppositely longitudinally extending upper torque rods connected at their remote ends :to said front and rear axles by universal joint connections above the longitudinal axis of each respective axle and connected at their adjacent ends by universal joint connections to said frame support brackets, lower torque rods in parallel relation to said upper torque rods connected at their remote ends to said front and rear axles by universal joint connections below the longitudinal axis of each respective axle and connected at their adjacent ends by universal joint connections to said frame support brackets, an upper steering arm fixed to one of the pivoted wheel mounting assemblies of each of said axles on the same side of said assembly, a pitman arm pivotally mounted in fixed relation to said frame mounting bracket substantially centrally with respect to the axle spacing of said tandem axle assembly, a forward adjustable length drag link rod connected at its opposite ends by universal joint assemblies to the upper steering arm of said front axle and to said pitman arm in predetermined spaced relation to the pivot axis of said pitinan arm, a rear adjustable length drag link rod connected at one end by a universal joint assembly to the upper steering arm of said rear axle and at the other end by a universal joint assembly to said pitman arm at a point located between said universal joint connection of said forward drag link rod and the pivotal axis of said pitman arm and nearer to the universal joint connection of said forward drag link rod, a main steering drag link movable under operator control connected by a universal joint assembly to said pitman arm at a point located between the pivotal axis of said pitman arm and the universal connection to said rear drag link rod and nearer to said rear drag link rod, a lower steering arm on each said pivoted wheel mounting assembly, and a cross tube associated with each axle and connected by universal joint assemblies to the lower steering arms thereof.

2. In the tandem axle ass y defined in aim 1, rigid sway bar member having a universal joint adapted for connection with the vehicle frame at one end and a universal joint connection with an axle of said tandem axle assembly at the other end, said sway bar member extend ng, when .in ope ativ p si o generally transversely Qfsaid fram 3.1n the tandem axle assembly defined in claim 1, lateral stabilization means for connection to said vehicle frame :and connected to each axle of said tandem axle assembly comprising an equalizer arm pivotally mounted .at-its ,rnid pchl i eac ax a pa of pp t y e al y extending nods each connected by universal joints at one end ;to one end of said equalizer arm and adapted at the other :end for universal connection to one side of 

